(We have a survey that pops up randomly when receipts print out. The customers can go to a website and receive a code for a free sandwich upon completion of the survey. We only accept receipts with the codes written on it.)

Me: “Do you have a coupon for me, sir?”

Customer:*hands me coupon* “I’d like to redeem my free sandwich.”

Me:*looks at coupon* “Sir, there is no code on this receipt. I cannot accept this coupon.”

(The customer rips it out of my hand, tears it up into several pieces and throws it on the floorboard.)

Friend: “We’ll just pay for the sandwich, then.”

(Still infuriated, the customer picks the receipt pieces back off the floorboard and continues to rip them into smaller pieces, throwing them back on the ground.)